Gaius Plinius Secundus, HN  35.126 (ca. A.D. 65):

Pausias autem fecit et grandes tabulas, sicut spectatam in Pompei porticu bovum immolationem.

However, Pausias also made large pictures, for example the Sacrifice of the Oxen which has been seen in the porticus of Pompeius. (U. K. Vestal, trans.)